5 курс / Пульмонология и фтизиатрия / Clinical_Manifestations_and_Assessment_of_Respiratory
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occur with use of these agents and to help improve the penetration and distribution of the drugs throughout the airways.
Recommended bronchodilators include beta2-adrenergic agonists such as the short-acting agent albuterol or long-acting
agents such as salmeterol or formoterol. The anticholinergic agent ipratropium bromide and the longer acting tiotropium are also used to treat patients with CF.
•Mucolytic agents
•Inhaled DNase (dornase alpha) (Pulmozyme) has been shown to be especially helpful in the management of patients with moderate to severe CF. This aerosolized agent is an enzyme that breaks down the DNA of the thick bronchial mucus associated with chronic bacterial infections with CF. Dornase alpha has shown good results in improving the lung function of patients with CF while reducing the frequency and severity of respiratory infections (Fig. 15.9).
FIGURE 15.9 Dornase alpha (Pulmozyme). Illustration of the mode of action of dornase alpha in reducing DNA polymers in cystic fibrosis sputum. Confocal micrograph showing cystic fibrosis sputum stained (with YOYO-1) for DNA before (A) and after (B) treatment with dornase alpha in vitro. The long DNA polymers are degraded into short units after dornase treatment. (From Gardenhire, D. S. [2016]. Rau's respiratory care
pharmacology [9th ed.]. St. Louis, MO: Elsevier.)
•Inhaled hypertonic saline may be administered to help hydrate thick mucus in the airways of patients with CF who are 6 years of age or older, have a chronic cough, and have a reduced FEV1. A typical treatment regimen is, first, the administration of a bronchodilator (e.g., albuterol), followed by 4 mL of a 3% to 7% saline solution, twice a day.
•Inhaled N-acetylcysteine has not been clinically proved to be effective in treating patients with CF. In addition, because of its potential to cause airway inflammation and/or bronchospasm and inhibit ciliary function, along with its disagreeable odor and relatively high cost, its use is not recommended (see Protocol 10.4: Aerosolized Medication Protocol, and Appendix II on the Evolve site).
Mechanical Ventilation Protocol
Because acute ventilatory failure superimposed on chronic ventilatory failure is occasionally seen in patients with severe CF, mechanical ventilation may be required to maintain an adequate ventilatory status. Continuous mechanical ventilation is justified when the acute ventilatory failure is thought to be reversible—for example, when pneumonia complicates the condition. Noninvasive ventilation, such as bilevel positive-pressure ventilation by face mask, is generally preferred to intubation when feasible (see Ventilator Initiation and Management Protocol, Protocol 11.1, and Mechanical Ventilation Weaning Protocol, Protocol 11.2).
Other Medications and Special Procedures Prescribed by the Physician
CFTR Modulators
Much of the current research in CF is focused on correcting the cellular defects in CF. Small molecules (medications that work when taken by mouth) that can help CF-mutated cells function more normally are being studied to improve the ability to treat CF. These medications are designed to treat the underlying cellular defects in CF rather than secondary complications of CF, which have been the focus of medical therapy of CF for the past 50 years.
Correctors are drugs that help mutated CFTR reach the epithelial cell surface where the CFTR protein normally functions as a transmembrane regulator of chloride movement out of the cell and sodium transport into the cell. Potentiators are drugs that help mutated CFTR function more effectively at the epithelial cell surface transporting chloride out of the cell and inhibiting the movement of sodium into the cell. Correctors are often designed to work on a specific CF mutation or class of mutations (e.g., mutations that alter proper folding of the CFTR protein; ΔF508 is this type of mutation). Potentiators improve the function of mutated CFTR that has reached the epithelial cell surface (gating mutations; G551D is this type of mutation) and are somewhat less mutation specific.
Ivacaftor (Kalydeco) is a new oral potentiator molecule that has been proved effective to improve cell function and clinical status in patients with CF with the G551D mutation. It was approved by the US Food and Drug Administration (FDA) in 2013 for patients over 6 years of age with CF with the G551D mutation. Ivacaftor is the first drug developed that targets the underlying causes of CF, the faulty CF gene G551D, and its defective CFTR protein. Ivacaftor appears to be remarkably effective for this mutation, significantly reducing sweat test values and improving lung function and weight gain. Unfortunately, the G551D mutation occurs in only 3% to 5% of all patients with CF. All patients with CF should have CFTR genotyping performed to determine if they carry the G551D mutation and could benefit from this breakthrough drug. Ivacaftor has now been approved for several other gating mutations.
Lumacaftor/ivacaftor (Orkambi), for patients who are homozygous for delta F508, combines a corrector and potentiator
43 mEq/L, PaO
FIGURE 15.10 Chest x-ray film from a 27-year-old man with cystic fibrosis.
Respiratory Assessment and Plan
S “I've not been this short of breath in a long time.”
O Known CF patient. Skin: Pale, cyanotic; barrel chest, and use of accessory muscles of respiration; digital clubbing; cough frequent and productive; sputum: sweet-smelling, thick, yellow-green; distended neck veins and peripheral edema; vital signs: BP 142/90, HR 108, RR 28, T° normal; bilateral hyperresonant percussion notes; diminished breath sounds; coarse crackles;
CXR: Hyperlucency, flattened diaphragms, and mild cardiac enlargement; ABGs
(1.5 L/min O2 by nasal cannula): pH 7.51, PaCO2 58, 
43, PaO2 66; and SaO2
94%.
A
•Respiratory distress (general appearance, vital signs)
•Excessive tracheobronchial tree secretions (productive cough, coarse crackles)
•Infection likely (yellow-green sputum)
•Hyperinflated alveoli (barrel chest, use of accessory muscles, CXR)
•Acute alveolar hyperventilation superimposed on chronic ventilatory failure with mild hypoxemia (history, ABGs)
•Possible impending acute ventilatory failure
•Cor pulmonale (distended neck veins, peripheral edema, CXR)
P Airway Clearance Therapy Protocol (cough and deep breathe Tx q4 h), sputum culture). Oxygen Therapy Protocol (2 L/min by nasal cannula). Monitor possible impending ventilatory failure closely (pulse oximetry, vital signs, ABGs).
Forty-Eight Hours After Admission
The respiratory therapist from the consult service noted that the patient was still in respiratory distress. The man stated that he could not get enough air to sleep even 10 minutes. He appeared cyanotic and was using his accessory muscles of respiration. His vital signs were blood pressure 147/95, heart rate 117 beats/min, respiratory rate 32 breaths/min, and temperature 37°C (98.6°F).
He coughed frequently, and although his cough was weak, he produced large amounts of thick, green sputum. Hyperresonant notes were produced during percussion over both lung fields. On auscultation, breath sounds and heart sounds were diminished. Coarse crackles and wheezing were heard throughout both lung fields. No recent chest x-ray film was available. A sputum culture obtained at admission suggested the presence of Pseudomonas aeruginosa. On a 2 L/min
oxygen cannula, his SpO2 was 92% and his ABGs were pH 7.55, PaCO2 54 mm Hg, 
45 mEq/L, PaO2 57 mm Hg, and SaO2 93%.
On the basis of these clinical data, the following SOAP was documented:
Respiratory Assessment and Plan
S “I can't get enough air to sleep 10 minutes!”
O Cyanosis and use of accessory muscles of respiration; vital signs: BP 147/95, HR 117, RR 32, T 37°C (98.6°F); cough: frequent, weak, and productive of large amounts of thick, green sputum; Pseudomonas aeruginosa cultured; bilateral hyperresonant notes and diminished breath sounds; coarse crackles and wheezes; on a 2 L/min oxygen cannula, SpO2 92%. ABGs:
pH 7.55, PaCO2 54, 
45, PaO2 57, and SaO2 93%. A
•Continued respiratory distress (general appearance, vital signs, use of accessory muscles)
•Excessive bronchial secretions (cough, sputum, coarse crackles)
36 mEq/L, PaO
36, PaOlong-term prognosis, as is the skill of the practitioner caring for him during this episode of acute ventilatory failure.
Self-Assessment Questions
1. Which of the following organisms is(are) commonly found in the tracheobronchial tree secretions of patients with cystic fibrosis?
1.Staphylococcus
2.Haemophilus influenzae
3.Streptococcus
4.Pseudomonas aeruginosa
a.1 only
b.2 only
c.1 and 4 only
d.1, 2, and 4 only
2.When two carriers of cystic fibrosis produce children, there is a: 1. 75% chance that the baby will be a carrier
2. 25% chance that the baby will be completely normal
3.50% chance that the baby will have cystic fibrosis
4.25% chance that the baby will have cystic fibrosis
a.1 only
b.3 only
c.2 and 4 only
d.1 and 2 only
3.The cystic fibrosis gene is located on which chromosome?
a.5
b.6
c.7
d.8
4.In cystic fibrosis the patient commonly demonstrates which of the following? 1. Increased FEVT
2.Decreased MVV
3.Increased RV
4.Decreased FEV1/FVC ratio a. 1 only
b. 3 only
c. 3 and 4 only
d. 2, 3, and 4 only
5.During the advanced stages of cystic fibrosis, the patient generally demonstrates which of the following?
1.Bronchial breath sounds
2.Dull percussion notes
3.Diminished breath sounds
4.Hyperresonant percussion notes
a.1 and 3 only
b.2 and 4 only
c.1 and 4 only
d.1, 3, and 4 only
6.About 80% of all patients with cystic fibrosis demonstrate a deficiency in which of the following vitamins? 1. A
2. B
3.D
4.E
5.K
a.3 and 4 only
b.1, 4, and 5 only
c.2, 3, and 4 only
d.1, 3, 4, and 5 only
7.Which of the following agents targets the underlying cause of cystic fibrosis, the faulty gene G551D, and its defective CFTR protein?
a.Aztreonam
b.Ivacafor
c.Inhaled DNase
d.N-acetylcysteine
8.Which of the following is(are) mucolytic agents?
1.DNase
2.Pulmozyme
3.Tobramycin